Optical, mechanical, and moisture sorption properties of whey protein edible films

Abstract

The impact of protein and glycerol concentration on the optical, mechanical, and moisture sorption properties of whey protein isolate edible films was determined. The increasing of protein concentration leads to decreasing opacity and moisture adsorption of films but improving its tensile strength and elongation at break. Color parameters for all films remain constant and were not dependent on the film composition. Films with increasing glycerol concentration showed weakened mechanical resistance and higher moisture adsorption rates. Moisture sorption isotherms data were well described by GAB, Peleg, and Lewicki equations. These findings can be used to better design applications of whey protein films containing plasticizers, in order to optimize film formulation in a rational manner considering their practical use as protective coatings or edible packaging. Practical applications The increased interest in the development of edible films for food packaging applications has been raised to minimize the use of synthetic petroleum‐based polymers. Moisture sensitivity of films showed the capacity of such materials to modify their physical properties which are influenced by different relative humidity or temperature conditions. The results presented in this study, concerning optical, mechanical, and sorption properties of whey protein‐based edible films, would provide the scientific basis for developing functional protein films and their application for food products including nuts, seeds, fruits, or vegetables.

Development and evaluation of edible films based on cassava starch, whey protein, and bees wax

“…A similar situation occurs in the chromatic coordinates a∗ and b∗ with their mean values fluctuated between (-1.2 and -1.9) and (3.0 and 9.1), which denotes a location in the chromatic plane a∗b∗ in the gray area of the II quadrant. This situation configures the dry material in the CIE-L∗a∗b∗ colour space with a translucent appearance (the light passes but does not allow for the objects to be seen clearly), matte or not very bright, of a greenish-yellow colour, conferred mainly by the content of WP present [ 40 ]. With respect to the control samples, the b∗ chromaticity differences are highlighted, whose values were lower than all the treatments with an average value of approximately 0, given the zero contribution of the CS in yellow pigmentation.…”

Effects of Candelilla and Carnauba Wax Incorporation on the Functional Properties of Edible Sodium Caseinate Films

“…These observations only suggest that many factors have to be taken into account in order to provide desirable film flexibility. In addition, elongation at break strongly depends on the plasticizer concentration [ 51 ]. Candelilla and carnauba wax showed an anti-plasticizing effect on sodium caseinate films.…”

“…The tensile strength (TS), Young’s modulus (YM), and elongation at break (E) of the film pieces 25 × 10 mm in size were determined using a texture analyzer, TA-XT2i (Stable Microsystems, Haslemere, UK) according to the ASTM standard method D882 [ 51 ]. The film specimens were mounted in the self-tightening roller grips of the testing machine and stretched at the rate of 1 mm·s −1 until breaking.…”

Effect of Glycerol Content on the Properties of Potato Flour Films

“…Natural macromolecule materials, such as polysaccharides and proteins, are widely used to prepare biodegradable films. [ 2–4 ]…”